1. Field of the Invention
The invention relates to a method for producing disposable cutting blades with a profiled cross section for a device for chipping wood.
Furthermore, the invention relates to a disposable cutting blade with a profiled cross section for devices for chipping wood, comprising a base body with at least one precisely gaged guide path in a longitudinal direction, as well as at least one pressure surface opposing this guide path and at least one edge region spaced from the guide path with a cutting edge.
2. Discussion of Background Information
For a production of oriented strand boards (OSB) with high quality, the quality of the raw material, i.e., of the chips, is of particular importance. Furthermore, the accumulation of splinter particles should be kept as low as possible during a chip production. The main requirements for a chipping of the base material wood result therefrom, namely uniformity of the chips regarding the thickness and the length of the chips with straight-line cuts.
A constant thickness of the chips and the surface quality thereof can be achieved during the long-term operation of a chipping device by the wearing resistance of the edge of the blades. For a required chip length, scratching knives or scratching blades are used which, before a chipping-off of the wooden primary material, scratch this material. In this way, the chips produced have a desired or an approximately equal length.
In the working part of a device for chipping wood, which is usually disk-shaped, cutting blades and scratching knives or scratching blades are often separately positioned on the turning circle with blades directed perpendicularly to one another.
During operation of the above devices, a varying wear of the cutting blades and scratching blades can occur. In this manner, either the chip quality decreases or an expensive replacement of the damaged blades must take place.
For the purpose of illustration, wood chips that were separated by defect-free (sharp) blades can be seen in FIG. 3, while the effect of worn (dull) scratching blades on the chipping cut can be seen in FIG. 4.
In order to increase the efficiency of the operation of a device for chipping wood, it was already attempted to provide the scratching blades in the chip-removal tool in the form of an integral component.
According to EP 1 358 980 A, it is recommended to optimize the production and re-sharpening of two-dimensionally operating blades for chipping machines and, thus, the production of chips. These blades have a main edge and at least one separating edge, are embodied in one piece, and can be produced in one piece from commercially available standard blades without a problem in terms of grinding.
However, cutting blades of this type, which are not generally available on the market, have serious disadvantages.
An accurate bracing of the commercially available standard blades for a production of a blade, and an exact clamping of the manufactured or re-sharpened blades in the blade holder can only be achieved at high cost, since the blades are held via frictional fit by means of a clamping plate and chipping forces act intermittently on each blade during rotations of the blade ring, which forces can displace these blades. Subsequently, different chip thicknesses may arise.
Commercially available standard blades are rolled products, the deformation direction of which ultimately corresponds to the main edge direction and can disadvantageously affect an edge durability.
Furthermore, a grinding of a possibly hardened standard blade is disadvantageous because a grinding removal in the thin edge region of the blade can produce a material heating that leads to a softening of the blade. This applies in particular to cutting blades, which thus possibly have a higher wear after brief use.